planeWithPlaneIntersection, error in parallel plane test

[sand-box]

The function template <typename Scalar> bool pcl::planeWithPlaneIntersection (const Eigen::Matrix<Scalar, 4, 1> &plane_a, const Eigen::Matrix<Scalar, 4, 1> &plane_b, Eigen::Matrix<Scalar, Eigen::Dynamic, 1> &line, double angular_tolerance) in file intersections.hpp checks for parallel planes like this:

  double test_cos = plane_a_norm.dot (plane_b_norm);
  double upper_limit = 1 + angular_tolerance;
  double lower_limit = 1 - angular_tolerance;
  if ((test_cos > lower_limit) && (test_cos < upper_limit))
  {
      PCL_DEBUG ("Plane A and Plane B are parallel.\n");
      return (false);
  }

I think there a three issues with this code

• check for anti-parallel plane is missing (cos ~= -1)
• no need for second condition (test_cos < upper_limit)
• documentation says: \param[in] angular_tolerance tolerance in radians. In code the parameter is not used in radian domain.

Your Environment

• Operating System and version: ubuntu 14.04
• Compiler: gcc 4.8.5
• PCL Version: 1.7.2

Expected Behavior

Checking for anti-parallel planes, correct documentation.

[SergioRAgostinho]

Agreed! Something like this should do the trick

abs (plane_a_norm.dot (plane_b_norm)) > (1 - sin ( abs (angular_tolerance)))

Can you file a pull request with the changes?

Edit: mistake on the expression to be checked.

[SergioRAgostinho]

Closed by #1698.